Add chat_class example

Add example of using the included chat class "Chat" to the readme.

README.md

@@ -42,6 +42,24 @@ inputs = tokenizer.apply_chat_template(messages)
 print(tokenizer.decode(model.generate(**inputs)[0]))
 ```
 
+Alternatively, copy the included `chat_class.py` module into your local
+directory and just import the `Chat` class:
+```
+from chat_class import Chat
+chat = Chat()  # default args: Chat("mathewhe/DCLM-7B-Chat", device="cuda")
+
+# for one-off instructions
+instruction = "Write a list of ingredients for banana pudding."
+print(chat.instruct(instruction))
+
+# for multi-turn chat
+response1 = chat.message("Who was Stan Lee?")
+response2 = chat.message("What was his wife's name?")
+
+# to reset the chat
+chat.reset()
+```
+
 ## Chat template
 
 This model uses the following chat template and does not support a separate